News Article | November 17, 2016
Scientists studying the Chicxulub crater have shown how large asteroid impacts deform rocks in a way that may produce habitats for early life. Scientists studying the Chicxulub crater have shown how large asteroid impacts deform rocks in a way that may produce habitats for early life. Around 65 million years ago a massive asteroid crashed into the Gulf of Mexico causing an impact so huge that the blast and subsequent knock-on effects wiped out around 75 per cent of all life on Earth, including most of the dinosaurs. This is known as the Chicxulub impact. In April and May 2016, an international team of scientists undertook an offshore expedition and drilled into part of the Chicxulub impact crater. Their mission was to retrieve samples from the rocky inner ridges of the crater - known as the 'peak ring' - drilling 506 to 1335 metres below the modern day sea floor to understand more about the ancient cataclysmic event. Now, the researchers have carried out the first analysis of the core samples. They found that the impact millions of years ago deformed the peak ring rocks in such a way that it made them more porous, and less dense, than any models had previously predicted. Porous rocks provide niches for simple organisms to take hold, and there would also be nutrients available in the pores, from circulating water that would have been heated inside the Earth's crust. Early Earth was constantly bombarded by asteroids, and the team have inferred that this bombardment must have also created other rocks with similar physical properties. This may partly explain how life took hold on Earth. The study, which is published today in the journal Science, also confirmed a model for how peak rings were formed in the Chicxulub crater, and how peak rings may be formed in craters on other planetary bodies. The team's new work has confirmed that the asteroid, which created the Chicxulub crater, hit the Earth's surface with such a force that it pushed rocks, which at that time were ten kilometres beneath the surface, farther downwards and then outwards. These rocks then moved inwards again towards the impact zone and then up to the surface, before collapsing downwards and outwards again to form the peak ring. In total they moved an approximate total distance of 30 kilometres in a matter of a few minutes. Professor Joanna Morgan, lead author of the study from the Department of Earth Science and Engineering, said: "It is hard to believe that the same forces that destroyed the dinosaurs may have also played a part, much earlier on in Earth's history, in providing the first refuges for early life on the planet. We are hoping that further analyses of the core samples will provide more insights into how life can exist in these subterranean environments." The next steps will see the team acquiring a suite of detailed measurements from the recovered core samples to refine their numerical simulations. Ultimately, the team are looking for evidence of modern and ancient life in the peak-ring rocks. They also want to learn more about the first sediments that were deposited on top of the peak ring, which could tell the researchers if they were deposited by a giant tsunami, and provide them with insights into how life recovered, and when life actually returned to this sterilised zone after the impact. "The formation of peak rings in large impact craters", published Thursday 17 November in the journal Science. See paper for full list of authors. Imperial College London is one of the world's leading universities. The College's 16,000 students and 8,000 staff are expanding the frontiers of knowledge in science, medicine, engineering and business, and translating their discoveries into benefits for society. Founded in 1907, Imperial builds on a distinguished past - having pioneered penicillin, holography and fibre optics - to shape the future. Imperial researchers work across disciplines to improve health and wellbeing, understand the natural world, engineer novel solutions and lead the data revolution. This blend of academic excellence and its real-world application feeds into Imperial's exceptional learning environment, where students participate in research to push the limits of their degrees. Imperial collaborates widely to achieve greater impact. It works with the NHS to improve healthcare in west London, is a leading partner in research and education within the European Union, and is the UK's number one research collaborator with China. Imperial has nine London campuses, including its White City Campus: a research and innovation centre that is in its initial stages of development in west London. At White City, researchers, businesses and higher education partners will co-locate to create value from ideas on a global scale. http://www. Imperial College London academic experts are available for interview via broadcast quality Globelynx TV facilities and an ISDN line for radio at our South Kensington Campus. To request an interview, please contact a member of the communications team http://www. The expedition was conducted by the European Consortium for Ocean Research Drilling (ECORD) as part of the International Ocean Discovery Program (IODP). The expedition is also supported by the International Continental Scientific Drilling Programme (ICDP). The expedition would not have been possible without the support and assistance of the Yucatán Government, Mexican federal government agencies and scientists from the National Autonomous University of Mexico (UNAM) and the Centro de Investigación Científica de Yucatán (CICY).
Ritter E.,NEIKER |
Herran A.,NEIKER |
Valdes-Infante J.,IIFT |
Rodriguez-Medina N.N.,IIFT |
And 14 more authors.
Acta Horticulturae | Year: 2010
Integrated parental linkage maps have been constructed in three guava mapping populations ('Enana' × "N", 'Enana' × 'Suprema Roja' and 'Enana' × 'Belic L-207') based on AFLP and SSR markers. Between 102 and 119 AFLP primer combinations (PCs) were analysed in each population, generating between 684 and 1163 segregating AFLP fragments. The distribution of parent-specific and common markers indicated that 'Enana' is less heterozygous than the other parents and that all parents share a considerable gene pool. In addition, between 28 and 171 SSR PCs were analysed for linkage mapping in these populations. Initially parent specific linked fragments were arranged into linkage groups. In all mapping population, 11 linkage groups (LGs) corresponding to the 11 chromosomes of the haploid guava genome were obtained for each parent. Based on the available SSR markers, combined parental linkage maps of each mapping population were produced using as anchor points allelic SSR fragments and common AFLP fragments. These integrated maps contain between 408 and 850 markers and have lengths of 1885 to 2179 cM, respectively. Average linkage group lengths in these maps vary between 160 and 198 cM and contain on average between 37 and 77 markers. Several identical SSR markers were mapped in various progenies, and potential associations of linkage groups from different populations were detected. In the future, the number of common SSR markers has to be increased in order to achieve full alignment of all individual linkage maps into a high-density reference molecular linkage map of guava.
Yunez-Cano A.,National Polytechnic Institute of Mexico |
Gonzalez-Huerta R.D.G.,National Polytechnic Institute of Mexico |
Tufino-Velazquez M.,National Polytechnic Institute of Mexico |
Barbosa R.,University of Quintana Roo |
International Journal of Hydrogen Energy | Year: 2016
One of the most interesting energy development systems is the one based on hydrogen use and their integration with renewable energy sources. In fact, hydrogen can operate as a storage and carrying medium of these primary sources. An analytical model to size, analyze and assess the feasibility of a hybrid photovoltaic/hydrogen (PV/H2) energy conversion system using real weather data is presented in this work. The analysis considers an energy balance and electrical variables of the system components; the sub-systems efficacy are calculated and proposed the improvements to increase the efficiency, using surplus energy produced by hybrid system. Solar radiation measurements was gotten from a meteorological monitoring station which is placed in the roof of the sustainable house and located in Mexico City north side. The PV/H2 system delivered electric power from a primary source (PV) to feed the electric load and surplus energy is supplied to electrolyzer in order to generate hydrogen, while energy deficit hours a PEMFC covers part the electric demand. Therefore, the hybrid system efficacy is calculated by energy stored level and electric load required. © 2016 Hydrogen Energy Publications LLC
Castano E.,CICY |
Philimonenko V.V.,Academy of Sciences of the Czech Republic |
Kahle M.,Academy of Sciences of the Czech Republic |
Fukalova J.,Academy of Sciences of the Czech Republic |
And 5 more authors.
Histochemistry and Cell Biology | Year: 2010
Actin is a well-known protein that has shown a myriad of activities in the cytoplasm. However, recent findings of actin involvement in nuclear processes are overwhelming. Actin complexes in the nucleus range from very dynamic chromatin-remodeling complexes to structural elements of the matrix with single partners known as actin-binding proteins (ABPs). This review summarizes the recent findings of actin-containing complexes in the nucleus. Particular attention is given to key processes like chromatin remodeling, transcription, DNA replication, nucleocytoplasmic transport and to actin roles in nuclear architecture. Understanding the mechanisms involving ABPs will definitely lead us to the principles of the regulation of gene expression performed via concerting nuclear and cytoplasmic processes. © Springer-Verlag 2010.
Rosas-Durazo A.,CIAD Guaymas |
Lizardi J.,CIAD Hermosillo |
Higuera-Ciapara I.,CICY |
Arguelles-Monal W.,CIAD Guaymas |
And 2 more authors.
Colloids and Surfaces B: Biointerfaces | Year: 2011
The aim of this work was to develop and characterize a new type of nanocapsules. To this end, a nanoemulsion bearing an oily core (Miglyol 812) was obtained by spontaneous emulsification and stabilized by dodecyl-trimethylammonium chloride (DTAC), a commercial cationic surfactant; this nanoemulsion was coated with proportionally very small amounts of κ-carrageenan (at molar charge ratios of Z≤ 0.0045) that interact predominantly by an electrostatic mechanism with the positively charged sites at the polar heads of DTAC at the nanoemulsion's surface to harness nanocapsules of average size ∼250-330. nm and zeta potential (ζ) ranging from ∼+80 to +7. mV. The potential application of the new type of developed nanosystems as drug delivery vehicles has yet to be investigated and fully realized. © 2011 Elsevier B.V.
Rosas-Durazo A.,CIAD Guaymas |
Hernandez J.,University of Veracruz |
Lizardi J.,CIAD Hermosillo |
Higuera-Ciapara I.,CICY |
And 2 more authors.
Soft Matter | Year: 2011
The gelation processes taking place in the non-stoichiometric complex between κ-carrageenan and dodecyltrimethylammonium chloride in KCl were studied. The mechanical properties of the hydrogels show a gradual reinforcement when the amount of surfactant in the complex increases, indicative of a more densely cross-linked polymer network. The thermal and viscoelastic behavior of complexes during cooling is similar to that of κ-carrageenan alone. Nevertheless, the melting of the gel splits into two endothermic processes. The emergence of a new transition during heating indicates that the overall polymer network is related to two types of networks: one formed by typical bonds between κ-carrageenan macromolecular chains and the other associated to hydrophobic blocks developing as a consequence of the cooperative nature of polyelectrolyte-surfactant interactions. In the hydrogel these two networks co-exist, probably semi-interpenetrated, somehow interconnected at the molecular level. © 2011 The Royal Society of Chemistry.